Metal shopping carts (increasingly less common these days) would be good for:
-Transporting bulky items in urban terrain
-Material for animal cages and traps
-Panels for reinforcing/securing doors/windows
-Drying rack for clothing
-Filling with debris and used for barricades
WARNING: Don’t use wire panels from shopping carts for over-the-fire grills, unless you are certain what types of metals/coatings are on the steel. Some use anti-corrosion alloys that contain nasty stuff like zinc and cadmium to help prevent damage from outdoor storage. The same warning applies to the wire shelves found in old refrigerators.
However, they seem range limited (local, your homestead). The extended terrain is not generally conducive to smooth rolling castor wheels of small diameter like on these carts.
That just means that you’re using a “bone-stock” shopping cart. Move up to the “unlimited” class with a few mods, using salvaged items.